During a pedestrian impact event with a vehicle, it is well known that forces exerted on the pedestrian's body from a front portion of the vehicle (e.g., the bumper and/or grill) will often result in the pedestrian's body being moved in a manner that causes the pedestrian's head to impinge upon the hood of the vehicle. In certain vehicle designs, the clearance between the underside of the hood and the topmost surface of under-hood components of the vehicle offers limited downward deflection of the hood before the hood engages the topmost surface of such under-hood components. The portion of the hood engaged with the topmost surface of such under-hood components becomes, in effect, a non-compliant and/or non-deflecting (i.e., effectively solid) surface. As a result, during impingement of the pedestrian's head on the hood, engagement of the hood with the topmost surface of such under-hood components can contribute to serious head trauma as compared to if the hood was allowed to deflect in a more unrestricted manner.
In accordance with certain vehicle test protocols as related to pedestrian head impact protection, there needs to be a gap of more than about 75 mm between the underside of the hood of a vehicle and the topmost surface of its under-hood components. Existing design solutions to address pedestrian head impact protection include structures such as, for example, complicated multi-bar link hinges, difficult to package under hood/cowl airbags, spring assist hood lift mechanisms, hood attachment pin(s) that shear off before pedestrian head impact, and other complex and/or costly solutions. Invariably, cost of the system increases with complexity. Thus, there is a need for a cost-effective solution to pedestrian head impact protection that can be implemented with a variety of hood mounting arrangements, that is effective in its results, and that is simple to package in an under-hood environment.